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Climate Change

Climate has an enormous impact on society, with wide-ranging effects on public safety and health, the economy, transportation, infrastructure, and agriculture. Geoscientists investigate our climate’s past and present to better understand how it may change in the future.

The Basics

Climate is the average of weather conditions over decades to centuries in a particular location.[1] Climate is influenced by many factors, including solar activity, ocean circulation, land cover, and greenhouse gases and aerosols in the atmosphere.[2,3,4,5]

Records from Earth’s geologic history show that the climate has changed both gradually and abruptly in the past, and that global temperatures and the concentrations of greenhouse gases in the atmosphere are strongly correlated[6]. Many of the concerns over human influences on climate are due to the significant emissions of greenhouse gases from human activities since the mid-19th century[2,7]. Natural processes will always have strong effects on climate, but there is evidence that these greenhouse gas emissions, combined with other human activities such as aerosol emissions and land-use changes, are linked to the rapid warming that has been observed since the middle of the 20th century[2,3,4,7,8,9,10,11,12]. Since the start of the 20th century, average global temperatures have increased, with most of the warming occurring since the 1970s[7,8,9]. All 10 of the warmest years since records began have occurred since the early 2000s, and average global temperatures are expected to increase at least 2 ºF, and perhaps by as much as 11 ºF, over the next century[10,11].

How does geoscience inform decisions about climate?

The Earth system is a complex one, and it is not always easy to predict the precise effects of geological processes or human activities, particularly on geologically short timescales of years to decades. Geoscientists use historical measurements, data from the geologic record, and real-time data to constantly improve their understanding of the Earth system and to predict future climate changes due to both natural causes and human activities.

References

1 What’s the Difference Between Weather and Climate?, NASA

2 Climate Change Facts: Causes, NASA

3 2014 National Climate Assessment: Land Use and Land Cover Change, U.S. Global Change Research Program

4 FAQ: How do changes in climate and land use relate to one another?, U.S. Geological Survey

5 Aerosols: Tiny Particles, Big Impact, NASA

6 Temperature change and carbon dioxide change, National Oceanic and Atmospheric Administration

7 2014 National Climate Assessment: Future Climate Change, U.S. Global Change Research Program

8 Climate Change Facts: Evidence, National Oceanic and Atmospheric Administration

9 FAQ: Is the globe still warming today?, National Oceanic and Atmospheric Administration

10 Global Climate Change Indicators, National Oceanic and Atmospheric Administration

11 Advancing the Science of Climate Change, The National Academies

12 2014 National Climate Assessment: Recent U.S. Temperature Trends, U.S. Global Change Research Program

Learn More

Introductory Resources

  • Climate Change Evidence & Causes: The Basics of Climate Change, The National Academy of Sciences and U.K. Royal Society
    This in-depth web resource summarizes the basic science behind climate change and accompanies a report by experts at the U.S. National Academy of Sciences and U.K. Royal Society. The report presents evidence and explanation of climate change for the general public, structured around twenty common questions.

Resources for Educators

Additional Resources

Drought

Since 1980 the United States has experienced more than 24 major droughts, resulting in almost 3,000 deaths and economic impacts exceeding $225 billion.All areas of the U.S. have some drought risk.

Energy

All of the energy we use comes from the Earth, its atmosphere, or the Sun. Some resources are mined or extracted, like coal, uranium, oil, and gas. Others, like wind, solar, tidal, biomass, and hydropower resources, are harnessed at the Earth’s surface. Geoscientists play an essential role in developing energy resources and evaluating their environmental impacts.

Floods

Flooding is the most common and costliest natural hazard facing the United States. Each year, flooding causes billions of dollars in damages and dozens of deaths nationwide.

Water Availability

Water is constantly moving on the Earth between the atmosphere, ocean, rivers and streams, snowpacks and ice sheets, and underground. Water availability, both as surface water and groundwater, is essential for agriculture, human consumption, industry, and energy generation.

Water Quality

Water quality refers to whether water is suitable for a certain purpose, like drinking or irrigation. Both natural and man-made factors can affect water quality. Contaminants can include bacteria, metals, and man-made chemicals like pesticides or pharmaceutical drugs.

Weather Hazards

Weather hazards impact the entire country, with enormous effects on the economy and public safety. Since 1980, weather/climate disasters have cost the U.S. economy more than $1.5 trillion. In an average year, the United States will be affected by six billion-dollar weather/climate disasters, but this number has increased in recent years: from 2013-2017 the average was 11.6 events.

Wildfires

Wildfires are causing more frequent and wider-ranging societal impacts, especially as residential communities continue to expand into wildland areas. Since 2000, there have been twelve wildfires in the United States that have each caused damages exceeding $1 billion; cumulatively, these twelve wildfires have caused a total of $44 billion in damages.